Hello Pauwhoovie16
No, this is not possible because this combination is not allowed when using IC or IR trains.
You need a return ticket from Zürich Airport to Wil, plus the OSTWIND 9 o’clock Day Pass All Zones since the Ostwind Day Pass is not valid to Winterthur.
A Saver Day Pass might be cheaper and valid for the whole trip.
Kind regards,
Roland